Turbo or Valve seals?

[shockracer]

Not sure if it's the valve seals or the turbo. she only smokes if i let her sit and idle for a min or two, if i sit longer it gets worse. so if i see some smoke I'll boost her and after 20-25 sec's it will clear up. just a little bit of shaft play left to right is all, no in and out.

what are your guy's experience's with a situation like this?

thx guy's, Joe

 

[LiquidX]

A leak down test (if I'm correct) would determine if your valve seals are bad. How slight is the shaft play? Do the blades touch the wall or is it normal play?

Usually you'll smoke in higher RPMs if the turbo seals are bad due to higher oil pressure pushing past the seal and into the turbine/hot exhaust gas.

 

[shockracer]

normal play i would say, the fines don't touch at all.

 

[JusMX141]

Valve seals. Turbos generally do not smoke at idle when the oil pressure is the lowest unless there is some ridiculous shaft play.

 

[shockracer]

Well thx guy's, looks like im in for some fun

Is it posible to change out the seals on the 4g63 head with out removing the cams?

 

[JusMX141]

Is it posible to change out the seals on the 4g63 head with out removing the cams?

Being that the cams sit directly on top of the valves, I believe the answer to this would be "no".

 

[shockracer]

OK well thanks, i guess they will be done with the timing belt then.

 

[JusMX141]

Use the long threaded tool to compress the auto tensioner, zip-tie the belt to the cam gears, then remove one cam at a time while you do the valve seals.

Of course, I've never done seals with the head on the car so I can't offer any advice as to how difficult this will be. It's a bi*** of a job even with the head off the car, so I can't imagine how hard it may be with the head still on the car.....perhaps those who have done it this way can offer some insight.

 

[romeen]

Cams definitely need to come out.

It's not that hard to change the seals with the head on if you have the right tools. This valve spring compressor can be used with the head on or off and is much faster than traditional spring compressors (but it does take some muscle and may be difficult to use with stiffer springs).

GA317, Remover/Installer, Metric Valve Keeper

You will also need some way to keep the valves from dropping. An air compressor connected to the cylinder via a leak down tester or just an air line with an adapter is ideal. The "rope" method supposedly works good but I have never personally tried it.

A leak down test (if I'm correct) would determine if your valve seals are bad.

A leak down test will test the seal between valve/valve seat and shouldn't allow air into the intake port unless the intake valves are not sealing. The stem seals shouldn't be seeing any pressure.

But you can do a boost leak test with the valve cover off to try to detect air getting the past the seals.

 

[shockracer]

But you can do a boost leak test with the valve cover off to try to detect air getting the past the seals.

I will try this to be curtain, thanks! i'd hate to tare stuff apart when it is just fine, so preforming a Boost leak teat and checking the valve seals is the cheapest way to check/ put back together with out spending to much (just incase it's not that)

Thanks for the info guy's!!

 

[kawgomoo]

Valve seals. Turbos generally do not smoke at idle when the oil pressure is the lowest unless there is some ridiculous shaft play.

We have to agree to disagree on this one....though i dont disagree his car needs valve seals.

I have a turbo that smokes like a bi***, yet has no shaft play.

Stock real evo3 turbo, not the chinabay one.

It just dried out from sitting in the driveway for years...and years...and years.

But i digress. If the smoke goes away when you rev the engine then i say valve seals.

If it gets worse with acceleration then i say turbo.

i know this is resolved...but just for people trying to diagnose there own in the future i hope it helps a little bit